Re: Lock File

Here is a technique that I picked up here at the monastery a few years back, and have been using ever since:

use Fcntl 'LOCK_EX', 'LOCK_NB';

unless (flock DATA, LOCK_EX | LOCK_NB) {
    $logger->fatal("Found duplicate script run. Stopping");
    exit;
}

__DATA__
This exists to allow the locking code at the beginning of the file to 
+work.
DO NOT REMOVE THESE LINES!
[download]

If I can find the original node, I'll update with a link to it.
Update: Found it. this node by adamk.

Cheers,
Darren

Comment on Re: Lock File Download Code

Replies are listed 'Best First'.
Re^2: Lock File by eyepopslikeamosquito (Archbishop) on Nov 03, 2010 at 08:44 UTC
As discussed in Ensuring only one copy of a perl script is running at a time, be aware that this trick works on Unix (with advisory locking), but does not work on Windows (mandatory locking).	[reply]
Re^2: Lock File by JavaFan (Canon) on Nov 03, 2010 at 13:28 UTC
You actually don't need the latter two lines. Just having either `__DATA__` or `__END__` will do.	[reply] [d/l] [select]
Re^3: Lock File by Anonymous Monk on Nov 03, 2010 at 16:38 UTC
The text after the `__DATA__` is required. Without it, the program will stop working as soon as a coworker tries to improve the code. :P	[reply] [d/l]